2D Image to 2.D image

[danics]

i search for an algorithm for generating a 2.5D image or 3d Image from 2d tiled or a vector image, actually i want to create a plugin for OpenCPN So that its maps when zoom in looks like 3D (like Nokia Drive+ application) and when zoom out its back to 2d maps.

thanks in advance.

[seandepagnier]

Do you need topography? I am not sure what nokia drive looks like. What is the purpose of this feature?

[danics]

this is a image for nokia drive in zoom in mode

http://images.anandtech.com/doci/526...e-25_575px.jpg

i believe this is just a rotation algorithm and using distance of the objects form each other, we have this variable in our maps too, so i want create a feeling of 3d map so i called it 2.5d image

[seandepagnier]

You can probably just modify the projection matrix at least in opengl mode to get this effect. This would take one line of code. What is the advantage of this mode?

[Baikal]

Originally Posted by boat_alexandra

You can probably just modify the projection matrix at least in opengl mode to get this effect. This would take one line of code. What is the advantage of this mode?

a function display is in cartography C-MAP MAX
http://www.marinecommander.co.uk/sys...en04_large.jpg

open up more spaces from the front, not more

[seandepagnier]

Originally Posted by Baikal

a function display is in cartography C-MAP MAX
http://www.marinecommander.co.uk/sys...en04_large.jpg

open up more spaces from the front, not more

This is incredibly easy to implement for both vector and raster charts. There are two possible options.. If you want the icons and other bitmaps to be projected or not. Consider also things like grib wind arrows. If you want them projected, then using the framebuffer object will be required and it's all a bit more complicated but still possible, at least in opengl mode.

I would try messing with the other axes in the glRotated call besides only the z axis before swapping buffers. You will need to extend the viewport class to include these angles, and have it calculate the lat-lon bounding box accordingly, and extend the routines that compute screen coordinates from lat/lon and lat/lon from screen coordinates. This is a matter of applying a matrix multiplication instead of the sine and cosine used for simple viewport rotation.

Some kind of guard is needed as this will only work in opengl mode, at least for raster charts. For vector charts it should work in non opengl mode as well.

I personally would like to go a bit further, and implement vector and fragment shaders to convert to polar, and ellipsoidal coordinates on the fly as well. This can work in conjunction with a projected viewport.

[Baikal]

I think that is a perspective view of the map for raster and vector did not prevent - even though the practicality of this particular function can not see. More advantage of multiple viewports with the charts in CPN